At a press conference with Nigerian President Goodluck Jonathan on Monday, Hollande initially observed somberly that the Catholic church should be left in peace to organize Benoit's succession.
But he could not resist adding with a smirk: "We won't be putting up a candidate!"
The Socialist leader's irreverence at a time of great consternation for many Catholics was slammed as inappropriate by former interior minister Claude Gueant.
"Everyone knows that Francois Hollande is not very well disposed to religion in general and to the Catholic church in particular," Gueant told Canal + television.
"But to make a joke about such a dignified decision is not good at all. It is completely out of place."
Gueant also took a swipe at Hollande's minister for older people, Michele Delaunay, who tweeted under the hashtags #Age and #JobsforSeniors: "I have to admit that, rightly or wrongly, Benoit XVI failed to consult me before taking his decision." She later deleted the message.
Gueant commented: "They are joking about someone of such stature, it's really not very good at all."
Hollande, who was brought up by Catholic parents and attended a private Catholic school, has been widely described as an atheist. Jealously protective of his private life, he has only confirmed that he does not practise any religion while having respect for all faiths.
The president's domestic arrangements are certainly not compatible with Catholic teaching. Hollande lives with his glamorous girlfriend, Valerie Trierweiller, for whom he left the mother of his four children, whom he never married.